On his foreign travels this week, Barack Obama, the Democratic presidential candidate, pledged to switch the focus of America's military effort from Iraq to Afghanistan - the 'central front' - in his estimation of the war on terror. US combat troops would be withdrawn from Iraq within 16 months of his taking office, but thousands more, he promised, would be sent to fight in Afghanistan, and be ready to cross the border into Pakistan's tribal areas to root out jihadist sanctuaries there.

This commitment - and the explicit threat to expand the war - is almost certainly a grave mistake. Costly in men and treasure, it is unlikely to be successful and threatens to be hugely damaging not only to American interests in the Muslim world and Central Asia, but also to Afghanistan itself, to Pakistan and to Indo-Pakistan relations.

No doubt, Obama senses that the American public yearns for some sort of victory against Al Qaida, the elusive terrorist group that dared strike at America's heartland on 9/11. "Losing is not an option when it comes to Al Qaida..." he told CBS. He wants to look tough on security issues, where his rival John McCain seems to have an edge.

But this is to be a slave to old thinking, and in particular to a view of doubtful validity - but accepted as gospel by many Western politicians - that Western security depends on locating the ageing Osama Bin Laden in some remote mountain fastness, and destroying him.

This is to mistake the nature of the threat to Western societies. Far more dangerous than Al Qaida is the mass of angry tribesmen and city-dwellers in the Afghan provinces of Helmand and Kandahar, in Pakistan's Balochistan, in the tribal agencies of North and South Waziristan, in and around the teeming city of Peshawar, and even further afield in neighbouring Uzbekistan and Tajikistan.

These men, and many of their co-religionaries in the wider Muslim world, are angry because of America's "war on terror". For many of them, it has meant the presence of an "infidel" army in Muslim lands, the vast disruption of their traditional way of life, the killing of their wives and children by US air strikes, the flourishing of cruel and greedy warlords in outlying Afghan areas, and the rule in Kabul of President Hamid Karzai, seen as a Western puppet presiding over a corrupt and ineffective regime.

Military means

To pursue the battle against Al Qaida by military means is to awaken these powerful tribal and Muslim resentments - as well as to threaten the already precarious stability of Pakistan, a Muslim nuclear power of 165 million people locked in a dangerous confrontation with India in both Kashmir and Afghanistan.

Zbigniew Brzezinski, the former US national security adviser, is a rare American voice to say (in an interview with the Financial Times last Monday) that "putting more troops into Afghanistan is not the entire solution... we run the risk that our military presence will gradually turn the Afghan population entirely against us".

Gérard Chaliand, a French counter-terrorist expert, goes further still. "Victory is impossible in Afghanistan," he declared (in an interview with Le Monde, last Tuesday). "Today, one must attempt to negotiate. There is no other way... The insurgency is not led by Al Qaida on by foreign fighters. It is a Pashtun matter [the majority tribe in Afghanistan, with another 15 million members in Pakistan]. The Pashtuns are fighting first of all for themselves."

Marc Sagemen, a leading American expert on Muslim extremism, argues in his book, Leaderless Jihad, that free-lance radicals are more of a threat to Western interests than Al Qaida itself which, he claims, has already been "neutralised operationally".

Another important book which denounces America's obsession with destroying Al Qaida is Ahmad Rashid's Descent into Chaos: How the War Against Islamic Extremism is Being Lost in Pakistan, Afghanistan and Central Asia. He argues that the neo-con obsession with Al Qaida has blinded the US to the impact of the war on Afghanistan, Pakistan and Kashmir, leading in turn to the powerful resurgence of the Taliban on both sides of the Afghan-Pakistan border.

It is surely the greatest folly for Nato to declare - and seemingly to believe - that its survival as an alliance, and indeed its very raison d'être, depends on victory in the Afghan theatre, a war that is virtually unwinnable.

Not the least of the problems is the underlying tension in Afghanistan between India and Pakistan, greatly exacerbated by this month's suicide car bomb outside the Indian embassy in Kabul which killed 58 people. India blamed the atrocity on Pakistan's Inter-Service Intelligence directorate (ISI), a charge that Pakistan vigorously denies.

It needs to be said, however, that Pakistan's military establishment views Afghanistan as its "strategic depth" in any conflict with India. It is ready to employ strong-arm tactics to ensure that the Kabul government tilts its way rather than India's.

Anti-American sentiment

With anti-American sentiment running high in Pakistan, the coalition government of Prime Minister Yousuf Raza Gilani has no wish to get sucked into America's "war on terror". It is seeking to negotiate with militant leaders in the tribal agencies, not make war on them, as America is urging. Obama's pledge to order military strikes against terrorist sanctuaries in Pakistan is viewed in Islamabad as highly irresponsible.

As is now widely recognised, Muslim radicals throughout the world have been inflamed by the wanton destruction of Iraq, by the war in Afghanistan, by Israel's cruel oppression of the Palestinians, and by the whole notion of the "war on terror", seen as a war on Islam itself. The way to defuse the threat the radicals pose is to change the policies. To seek to destroy them by military force is to radicalise them further.

Yet, in spite of the mass of evidence that force is not the way to tame the swelling army of militants, both US presidential contenders, Barack Obama and John McCain, speak of "turning around Afghanistan" by pouring in more troops. The sobering fact - confirmed by the US military - is that attacks by militants against the US-led coalition in Afghanistan have risen by 40 per cent this year, compared with 2007.

If not force, then what? Oxfam, the British humanitarian organisation, is not alone among NGOs in pleading for a change of focus. "Unless the next American president... builds on the existing commitments to help lift the Afghan people out of extreme poverty and protect civilians, it will be impossible for the country to achieve lasting peace," Oxfam said in a recent statement.

Afghanistan urgently needs an internationally-negotiated ceasefire followed by the formation of a new government, including the Taliban. It also needs a massive injection of development funds, distributed under neutral UN auspices. And, just as a resolution of the Arab-Israeli conflict is essential to end the violence in the Middle East, so a resolution of the Indo-Pakistan quarrel over Kashmir is vital to the health of the subcontinent.

These should be the priorities of the international community, rather than sending more young men to a useless death in the mountains and deserts of Afghanistan.

Patrick Seale is a commentator and author of several books on Middle East affairs.